Hitherto, polyester and polycarbonate resins have been modified with hydroxyphenyl group-containing silicone compounds for the purpose of improving physical characteristics such as flexibility, heat resistance, low temperature characteristics, etc., and surface characteristics such as slippability, water repellency, etc.
For instance, siloxane compounds represented by the general formula (II) are disclosed in U.S. Pat. Nos. 3, 182,662 and 3,419,634 as the compounds for producing silicone-modified polycarbonate resins: ##STR3##
While the foregoing siloxane compounds can readily undergo a modification reaction because their hydroxyl groups are located at the para-position of phenyl group, the polycarbonate resins produced, which have the following general formula (III), have a defect in that the stability to hydrolysis is low because of the introduction of Si-O-C linkage into the polymer chain: ##STR4##
Even if one thus wanted to produce such a hydroxyphenyl group-containing silicone as represented by the following formula, ##STR5## so that the Si-O-C linkage would not be contained, therein the corresponding silicone-modified polycarbonate resins cannot be obtained because the reactivity between the foregoing phenol compound and phosgene is low due to the presence of OH group at the ortho-position of phenyl group in the phenol compound.
As a result of concentrating our energies on obviating the above-described defects, it has now been found that a slioxane compound containing in a molecule at least one hydroxyphenyl group of the formula, ##STR6## is very useful in the production of silicone-modified polyester and polycarbonate resins, thus achieving this invention.